1. Field of the Invention
The present invention relates to an element which limits a movement of a head within a hard disk drive assembly.
2. Background Information
Hard disk drives contain transducers that are magnetically coupled to one or more rotating disks. The transducers can write and read information by magnetizing the disk surface and sensing the magnetic field that flows from the disks, respectively. The transducers are integrated into a head that is mounted to a flexure arm. The head and flexure arm are typically referred to as a head gimbal assembly (HGA).
The HGA""s of a hard disk drive are mounted to an actuator arm that is pivotally connected to a base plate of the drive. The drive may further include a voice coil motor that rotates the actuator arm and moves the heads across the surfaces of the disks.
The disk drive may have a number of disks that are stacked onto a spin motor. There may be an HGA associated with each disk surface. The HGAs may be attached to the actuator arm so that rotation of the arm causes a corresponding movement in all of the heads. The actuator arm may have a plurality of beams that each support a pair of HGAs. Some disk drives are manufactured without a head coupled to every disk surface of the drive. To maintain the mechanical characteristics of the actuator arm assembly, xe2x80x9cdummyxe2x80x9d non-active HGAs are typically attached to the actuator arm beams in lieu of the missing heads.
Each head has an air bearing surface which cooperates with an air flow generated by the rotating disks to create an air bearing between the head and the disk surfaces. The air bearing prevents mechanical wear between the disks and the heads.
The heads are essentially suspended from the actuator arm above or below the surfaces of the disks. Any shock or vibration loads essentially perpendicular to the disk surfaces may cause the heads to strike or xe2x80x9cslapxe2x80x9d the disks. Head slapping may damage both the heads and the disk.
Head slapping typically occurs when the shock load is great enough to cause the head to xe2x80x9cseparatexe2x80x9d away from the disk surface. The beams of the top and bottom actuator arm assemblies are typically thinner than other actuator arms since only one HGA is mounted to the actuator arm. This design minimizes the overall ass movement of inertia for faster seek times. In these cases, the largest head slapping forces are typically associated with the top and bottom HGAs located adjacent to the base plate and the cover plate of the drive. There is also a relatively large amount of space between the plates and the top and bottom HGAs. The large spaces allow the heads to move away from the disk surfaces and then slap back onto the disks.
The force required to create a head slap can be increased by reducing the length of the flexure arm. However, reducing the length of the arm may create an undesirable change in other mechanical characteristics, such as larger actuator arm swing, for example, on the hard drive assembly. It would be desirable to provide a hard disk drive that limits the movement of an HGA within the disk drive. It would also be desirable to limit the movement of the HGA without increasing the overall height of the hard disk drive.
One embodiment of the present invention is a hard disk drive assembly which includes a limiter plate that is attached to an actuator arm. The limiter plate limits a movement of a flexure arm that is attached to a head. The head is coupled to a disk.